Can't transport Ubuntu to another machine - fails dhcp connection

SES-Energy

8/18/24, 7:23 PM

I have an application running under Ubuntu 18.04 server which I've always been able to clone and move to another machine. When I create a 20.04 drive, I can move it to another machine with the same motherboard and it runs fine, but if I try a different motherboard, same manufacturer (ASRock), it will not pickup an IP address. My /etc/network/ directory is:

/etc/network$ ls -l
total 12
-rw-r--r-- 1 root root  245 Aug 11 14:40 dlc.yaml
drwxr-xr-x 2 root root 4096 Aug 31  2022 if-pre-up.d
drwxr-xr-x 2 root root 4096 Aug 31  2022 if-up.d

I know the .yaml file in /etc/netplan/ defines the interface 18.04 and beyond:

/etc/netplan$ cat 00-installer-config.yaml

# This is the network config written by 'subiquity'
network:
  ethernets:
    eno1:
      dhcp4: true
  version: 2

when working on the original installed system "ip a" is:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether a8:a1:59:d6:5f:2e brd ff:ff:ff:ff:ff:ff
    inet 192.168.0.116/24 brd 192.168.0.255 scope global dynamic eno1
       valid_lft 6555sec preferred_lft 6555sec
    inet6 fe80::aaa1:59ff:fed6:5f2e/64 scope link
       valid_lft forever preferred_lft forever

When I move it to another motherboard "ip a" is:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: enp6s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether a8:a1:59:a4:f4:f6 brd ff:ff:ff:ff:ff:ff

looking to have the system be able to pick up a dhcp IP address from a different box. The application running under the OS operates fine.

0 + 4

networking

dhcp

ip-address

Thomas Ward

8/18/24, 7:25 PM

You did change `eno1` to `enp6s0` in your netplan config right? Because otherwise it will say "OK, so I am configuring eno1 but it doesn't exist so nothing to do here!" if you don't update the ethernet interfaces in netplan

SES-Energy

8/20/24, 1:45 AM

I didn't edit netplan config, the .yaml file or change eno1 to enp6s0. I just moved the drive from one machine to another and when it booted in the original it was eno1. When I booted in another machine it was enp6s0.

Thomas Ward

8/20/24, 4:28 AM

That was your flaw. **You have to adjust your configuration for every machine it's installed on to properly match the target system.** OTHERWISE you will never *get* a configured Internet connection on your system. This is a limitation of Netplan based configurations, but is something you must do if you're going to use one drive on more than one system.

SES-Energy

8/24/24, 12:52 PM

If I run "dhclient" on the new system from the command line, it will pickup the IP address.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: Can't transport Ubuntu to another machine - fails dhcp connection

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